What type of damper is required to prevent the passage of flame and hot gases in certain duct systems?

A fire damper is specifically designed to protect against the spread of fire, smoke, and hot gases within duct systems. It is typically installed in ventilation ducts or air distribution systems that pass through barriers, such as fire-rated walls or ceilings. When a fire occurs, the damper will automatically close, restricting airflow and containing the fire and hot gases to a specific area. This critical function helps to prevent the escalation of the fire and allows for safer evacuation of occupants, while also protecting property and limiting the spread of damage.

In terms of its operation, fire dampers are usually equipped with fusible links or other heat-activated devices that react to elevated temperatures, prompting the damper to close at the appropriate moment. Therefore, it is vital that fire dampers are correctly installed according to the regulations set forth in the NC Mechanical Code to ensure they function effectively during an emergency.

This type of damper plays a crucial role in fire safety within buildings, especially in commercial spaces where extensive ductwork is common. The other options mentioned either serve different functions, such as regulating airflow or dealing with thermal radiation, but do not specifically address the necessary features required to contain flames and hot gases.